The proposed research will employ nuclear magnetic resonance (nmr) measurements of specifically labeled proteins to obtain details of enzyme conformation and mechanism including the properties of individual amino acid side chains and the consequences of conformational changes which accompany substrate binding, metal ion binding and subunit interactions. The enzymes to be studied include alkaline phosphatase labeled with 4-fluorotryptophan, m-fluorotyrosine or (gamma-13C)-histidine, aspartate transcarbamylase containing (gamma-13C)-histidine, (gamma-13C)-tyrosine, (gamma-13C)-phenylalanine, (gamma-13C)-tryptophan, or (beta-13C)-cysteine, tryptophan synthetase with 13C-enriched histidine or cysteine residues, and alcohol dehydrogenase specifically labeled using 19F-containing imido esters.